Portable devices such as cell phones and handheld computers are often charged by using a battery charger that couples to the cigarette lighter receptacle of a vehicle. During charging the cell phone remains fully functional for the user to make outgoing calls or to receive incoming calls. Sometimes the sounds being output by the radio while riding in a vehicle makes it difficult to hear a cell phone ring upon receipt of an incoming call, and/or the cell phone may not be equipped with display/keypad backlighting to alert the user to the incoming call. At other times, the cell phone may be resting in a position that prevents the user from seeing a visual indicator of an incoming call that is disposed on the phone preventing the user from being alerted to the incoming call. Accordingly, the present invention provides a cell phone battery charger for use in a vehicle that includes a means for providing a visual indication to the user that an incoming call is being received by the cell phone when the radio output level is high and when a visual indicator disposed on the phone cannot be seen due to the phones position.